1.With speed negative feedback automatically regulated, its speed rate of change: thefirst step<1.8%and the second step<2.5%.2.Without runaway area of speed with techogenerator gauging speed.3.Stable adjustable operating speed and wide range of adjustable speed, reaching 10:14.Good starting performance, smooth start and large moment.5.Simple reliable structure and convenient maintenance.6.Small power of controlling speed and easy to control in many ways.
